Problem: In 54 years, Christopher will be 4 times as old as he is right now. How old is he right now?
Solution: We can use the given information to write down an equation about Christopher's age. Let Christopher's age be $c$ In 54 years, he will be $c + 54$ years old. At that time, he will also be $4 c$ years old. Writing this information as an equation, we get: $c + 54 = 4 c$ Solving for $c$ , we get: $3 c = 54$ $c = 18$.